Sizing up my cassette, am I going crazy!

p1tse

I picked up a new 2012 cube agree gtc pro about 6 weeks ago
Newbie to it and only been out a half a dozen of times

Knowing I'll go for my 6 week service soon

Anyway it should be like this, with a shimano 105 11-28 cassette
viewtopic.php?f=40044&t=12865775

Looking to get a replacement cassette for spare turbo wheel I've just doubled checked and tried to count the small and large cog, but its counting 12-28 which shimano don't have (well not in wiggle online catalogue)

I'll treble check again in a bit, but do shimano have 12-28 cassette, or I'm miss counting or the bike shop has somehow managed to mess up build? Surely the latter shouldn't be as a cassette comes as a kit?

But then again I don't think I've ever managed to shift to the highest gear (smallest cog) on rear cassette

Thoughts?

ellj22

They do a 11-28 and a 12-27 but not a 12-28 in 105. I doubt the bike shop messed up build as usually cassette will be fitted to wheel when they receive it. Also if you read on most bike specs it does say 'bike spec may change without notice' or something along those lines.

The number of teeth should be stamped on the rings.

ellj22

Also if you has an 11-28 with a 12t ring in place of a 11t you will have 2 12t rings!

Sandy130674

Shimano do a 12-28 cassette, but it is Tiagra, not 105! I hope you haven't been fiddled.

p1tse

Newbie muppet
I googled the spec and it must have been a 2011 model with 105 11-28
Mines a 2012 and a bit more google search has come back it's a 12-28 tiagra!

So how does one tooth make a difference between the two (think 10 speed tiagra is new so shimano technology trickling down)
AND
I assume if I fitted a 105 11-28 on a spare training wheel it will be ok and compatible with current chain, crank, derailuer setup?

getprg

It is perhaps possible that the cassette is not Shimano 105 but the compatible 4600 Tiagra 12-28 10 speed cassette - see options here.

http://www.wiggle.co.uk/shimano-tiagra-4600-10-speed-cassette/?utm_source=google&utm_medium=base&utm_campaign=uk&utm_content=Shimano-Shimano_Tiagra_4600_10_Speed_Cassette-Silver

There is a 12-28 version listed.

You should be able to replace with 11-28 105 version if you prefer a higher top gear - although for most purposes (unless you are a very strong rider or racer) you are unlikely to regularly outspin a 12 tooth top gear!

You will need to check chain length and derailleur tooth capacity (see Shimano tech docs for 105) if changing rear cassette and increasing smallest/largest tooth capacity (in this case by one tooth). Chances are this will be within tolerances - Shimano tech docs tend to be conservative.

getprg

Mines a 2012 and a bit more google search has come back it's a 12-28 tiagra!

Doh - you beat me to it.

So how does one tooth make a difference between the two (think 10 speed tiagra is new so shimano technology trickling down)
AND
I assume if I fitted a 105 11-28 on a spare training wheel it will be ok and compatible with current chain, crank, derailuer setup?

Should be compatible but worth checking shimano online tech docs just in case. FWIW I have fitted oversize Tiagra 9 speed cassette to Tiagra compact which according to Tiagra tech docs was 2 teeth over total front and rear capacity and did not require chain lengthening.

getprg

Also worth bearing in mind that if you change cassette to 11- 28 you are likely to be changing a number of other rear ratios (not just the 12 to an 11).

If you need to use the trainer wheel for road riding (say in emergency) then your ratios will be out unless you switch cassettes.

Finally, its worth fitting a road/turbo compatible tyre to your trainer wheel for the same reasons - emergency use.

I use this one

http://www.ribblecycles.co.uk/sp/road-track-bike/tyres-road-tri-track-folding-continental-ultra-sport-folding-tyre/conttyrf225

But there are probably others.

p1tse

This place has it listed as 105 11-28

http://www.cyclesuperstore.ie/shop/pc/v ... duct=47647

A search showed someone on here emailing cube and said its a tiagra 12-28

To be honest I'm not bothered either way as a new tiagra will be similar to a 1-2 yr old design 105, and weight isn't an issue

p1tse

Took the wheel off to look
It says 12t on small cog
Shimano imprinted but no other branding on model so assume its the tiagra

Wiggle have these at £20, so will give the 11-28 105 a miss and sell it on

moscowflyer

I bought an Agree with Ultegra Di2 and I soon realised the cassette was a 12-28 Tiagra 4600. I queried it with the shop and they said this is what they come with as standard, even though other online retailers had it listed with the Ultegra cassette. I bought an Ultegra 12-25 anyway and changed it, so yours probably has the same as mine did.

keef66

Just a word of advice to anyone replacing a 10 speed Tiagra cassette with 105 or Ultegra. You'll need to ensure you install a thin spacer before the replacement cassette.

When Shimano went to 10 speed with Tiagra in their wisdom they made the cassette slightly wider to remove the need for the spacer.

smoggysteve

p1tse wrote:

Took the wheel off to look
It says 12t on small cog
Shimano imprinted but no other branding on model so assume its the tiagra

Wiggle have these at £20, so will give the 11-28 105 a miss and sell it on

Do you have a 1mm spacer behind the largest gear? If no it is deffo Tiagra as they don't require it like the 105 cassette.

Also a Tiagra would most likely be in a lot less separat parts to a 105. I think no more than 4. as in the 3 highest gears are loose the rest is one chunk of metal. 105 gears are loose up to about 5 rings.

moscowflyer

keef66 wrote:

Just a word of advice to anyone replacing a 10 speed Tiagra cassette with 105 or Ultegra. You'll need to ensure you install a thin spacer before the replacement cassette.

When Shimano went to 10 speed with Tiagra in their wisdom they made the cassette slightly wider to remove the need for the spacer.

Really? Hmmm, I didn't put one on mine (didn't realise I needed to) but it still rides absolutely fine though. Maybe I'll get hold of one.

moscowflyer

I've ordered a spacer to be on the safe side but would the cassette not have come with one anyway?

smoggysteve

A 105 would have.

moscowflyer

I've just had a look, there's nothing obvious on there, I assume it would be something like this;

http://www.wiggle.co.uk/shimano-cs-hg-1 ... et-spacer/

I've ordered it anyway so I'll have a look when it arrives and will fit it to see if it makes any difference.

smoggysteve

Should be a solid ring that looks like an oversized washer.

Think what you ordered should work, its just a metal spacer after all.

moscowflyer

Cheers.

It seems it may be a smaller one on there as per part number 14 here, which is why I can't see it looking down.

http://bike.shimano.com.sg/media/techdo ... 799947.pdf

There's definitely a gap between the largest cog and hub and no danger of rubbing so it must already be there. Always good to know something new though.

keef66

MoscowFlyer wrote:

I've just had a look, there's nothing obvious on there, I assume it would be something like this;

http://www.wiggle.co.uk/shimano-cs-hg-1 ... et-spacer/

I've ordered it anyway so I'll have a look when it arrives and will fit it to see if it makes any difference.

Nope, that's not it. Plain steel, 1.0mm thick, like a giant washer. Easy to miss, and might have come stuck to the back of your new cassette.

Edit:- yes, that's the one in the exploded diagram.

smoggysteve

The one he bought will still work, it just looks different.

styxd

If you have bought a new 105 cassette then it will be supplied with the necessary spacer.

With the 28/11 105 cassette you will find there is a larger "gap" between gears 5 and 6 - 5th gear is a 17t sprocket and 6th is a 15t. On your tiagra they are 17t and 16t.